Method for forming an electrical connection between an electronic chip and a carrier substrate and electronic device

ABSTRACT

An electrical connection wire connects an electrical connection pad of an electrical chip and an electrical connection pad of a carrier substrate to which the electronic chip is mounted. A dielectric layer surrounds at least the bonding wire. The dielectric layer may be a dielectric sheath or a hardened liquid dielectric material. A dielectric material may also cover at least a portion of the electrical chip and carrier substrate. A liquid electrically conductive material is deposited and hardened to form a local conductive shield surrounding the dielectric layer at the bonding wire.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional from U.S. application patent Ser. No.16/835,793 filed Mar. 31, 2020, which is a divisional from U.S. patentapplication Ser. No. 16/249,122 filed Jan. 16, 2019, now U.S. Pat. No.10,643,970, which is a divisional from U.S. patent application Ser. No.15/602,278 filed May 23, 2017, now U.S. Pat. No. 10,224,306, whichclaims the priority benefit of French Application for Patent Nos.1660622, 1660623, and 1660624, all filed on Nov. 3, 2016, thedisclosures of which are hereby incorporated by reference in theirentireties.

TECHNICAL FIELD

Embodiments relate to the field of electronic devices and, moreparticularly, to those which comprise electronic chips mounted oncarrier substrates, including electrical connection networks or leadframes, and electrical connection wires which connect the chips to thecarrier substrates.

BACKGROUND

In the case in which electrical connection wires convey signals, inparticular at high frequencies, these signals may be attenuated ordisrupted by surrounding electromagnetic fields and/or emitelectromagnetic fields which may disrupt the surroundings.

Currently, in order to manage this issue, it is proposed to add metalshielding plates, which are potentially connected to a ground, toelectronic devices. Nonetheless, positioning such metal shielding platesand electrically connecting them to a ground, combined with producingencapsulation blocks or putting encapsulation lids into place, posesproblems and is costly. Moreover, since the shielding obtained isnon-specific and located some distance away from the electricalconnection wires, the level of electromagnetic protection obtainedremains inadequate.

SUMMARY

According to one embodiment, a method is proposed for forming anelectrical connection between an electronic chip and a carrier substrateon which this chip is mounted.

The method comprises the following steps: placing an electricalconnection wire between an exposed electrical connection pad of theelectronic chip and an exposed electrical connection pad of the carriersubstrate and forming electrical junctions between the ends of this wireand the pads; producing a local dielectric coating made of a dielectricmaterial, which at least partially surrounds the electrical connectionwire and at least partially covers the pads and the junctions; andproducing a local conductive shield made of an electrically conductivematerial, which at least partially covers said local dielectric coating.

The local dielectric coating may be obtained by distributing adetermined amount of the dielectric material in the liquid state andhardening this dielectric material.

The local conductive shield may be obtained by distributing a determinedamount of an electrically conductive material in the liquid state andhardening this conductive material.

The distributing may be achieved by means of a controlled toolcomprising a dispensing syringe.

The local dielectric coating may completely surround the electricalconnection wire and completely covers the pads and the junctions and thelocal conductive shield may completely cover said local dielectriccoating.

The local dielectric coating may be produced so as to completelysurround the electrical connection wire and completely cover the padsand the junctions, and the local conductive shield may be produced so asto completely cover the local dielectric coating.

The method may additionally comprise the following steps: placing anadditional electrical connection wire between an exposed electricalconnection pad of the electronic chip and an exposed electricalconnection pad of the carrier substrate and forming electrical junctionsbetween the ends of this additional electrical connection wire and thesepads; and producing the local conductive shield such that this localconductive shield makes contact with this additional electricalconnection wire and/or with at least one of these electrical connectionpads.

An electronic device is also proposed which comprises: a carriersubstrate; an electronic chip mounted on the carrier substrate; at leastone electrical connection wire connecting an electrical connection padof the carrier substrate and an electrical connection pad of theelectronic chip; a local dielectric coating made of a dielectricmaterial at least partially surrounding the electrical connection wireand at least partially covering the electrical connection pads; and alocal conductive shield made of an electrically conductive material atleast partially covering the local dielectric coating.

The local dielectric coating made of a dielectric material maycompletely surround the electrical connection wire and may completelycover the pads and the junctions, and the local conductive shield maycompletely cover said local dielectric coating.

The device may additionally comprise at least one additional electricalconnection wire connecting an electrical connection pad of the carriersubstrate and an electrical connection pad of the electronic chip, thelocal conductive shield making contact with this additional electricalconnection wire and/or with at least one of these electrical connectionpads.

According to one embodiment, a method is proposed for forming anelectrical connection between an electronic chip and a carrier substrateon which this chip is mounted.

The method comprises the following steps: placing an electricalconnection wire between an exposed electrical connection pad of theelectronic chip and an exposed electrical connection pad of the carriersubstrate and forming electrical junctions between the ends of theelectrical connection wire and the pads, the electrical connection wirebeing equipped with an insulating sheath made of a dielectric materialwhich surrounds it; producing a local dielectric coating made of adielectric material, which at least partially covers at least one of thepads and the adjacent junction and at least partially surrounds anadjacent end portion of the insulating sheath; and producing a localconductive shield made of an electrically conductive material, which atleast partially covers said dielectric coating and at least partiallysurrounds the insulating sheath.

The local dielectric coating may be obtained by distributing adetermined amount of the dielectric material in the liquid state andhardening this dielectric material.

The conductive shield may be obtained by distributing a determinedamount of an electrically conductive material in the liquid state andhardening this conductive material.

The distributing may be achieved by means of a controlled toolcomprising a dispensing syringe.

The local dielectric coating may be produced so as to have a first localdielectric coating and a second local dielectric coating which cover thepads and the adjacent junctions and surround the adjacent end portionsof the insulating sheath, respectively, and the local conductive shieldmay be produced so as to cover the local dielectric coating and tosurround the insulating sheath.

The method may additionally comprise the following steps: placing anadditional electrical connection wire between an exposed electricalconnection pad of the electronic chip and an exposed electricalconnection pad of the carrier substrate and forming electrical junctionsbetween the ends of this additional electrical connection wire and thesepads; and producing the local conductive shield such that this localconductive shield makes contact with this additional electricalconnection wire and/or with at least one of these electrical connectionpads.

An electronic device is also proposed which comprises: a carriersubstrate; an electronic chip mounted on the carrier substrate; at leastone electrical connection wire connecting an electrical connection padof the carrier substrate and an electrical connection pad of theelectronic chip, this electrical connection wire being equipped with aninsulating sheath made of a dielectric material which surrounds it; alocal dielectric coating made of a dielectric material at leastpartially covering at least one of the electrical connection pads and atleast partially surrounding at least one adjacent end of the insulatingsheath; and a local conductive shield made of an electrically conductivematerial at least partially covering the dielectric coating.

The local dielectric coating may be produced so as to have a first localdielectric coating and a second local dielectric coating whichcompletely cover the pads and the adjacent junctions and completelysurround the adjacent end portions of the insulating sheath,respectively, and the local conductive shield may completely cover thedielectric coating and surrounds the insulating sheath.

The device may comprise at least one additional electrical connectionwire connecting an electrical connection pad of the carrier substrateand an electrical connection pad of the electronic chip, the localconductive shield making contact with this additional electricalconnection wire and/or with at least one of these electrical connectionpads.

According to one embodiment, a method is proposed for forming anelectrical connection between an electronic chip and a carrier substrateon which this chip is mounted.

The method comprises the following steps: placing at least oneelectrical connection wire between an exposed electrical connection padof the chip and an exposed electrical connection pad of the carriersubstrate and forming electrical junctions between the ends of the wireand the pads; producing a dielectric layer made of a dielectric materialon top of a zone of the electronic chip and of the carrier substrate,including the electrical connection wire, the junctions and the pads,such that this dielectric layer forms a local dielectric coating whichat least partially surrounds the electrical connection wire and at leastpartially covers the junctions and the pads; and producing a localconductive shield made of an electrically conductive material which atleast partially covers the local dielectric coating.

The dielectric layer including the local dielectric coating may beobtained by distributing a determined amount of the dielectric materialin the liquid state and hardening this dielectric material.

The dielectric material may be distributed by means of sputtering (suchas spraying).

The local conductive shield may be obtained by distributing a determinedamount of an electrically conductive material in the liquid state andhardening this conductive material.

The conductive material may be distributed by means of a controlled toolcomprising a dispensing syringe.

The local dielectric coating may be produced so as to completelysurround the electrical connection wire and to completely cover the padsand the junctions and the local conductive shield may be produced so asto completely cover said local dielectric coating.

The method may additionally comprise the following steps: producingopenings in the dielectric layer above additional electrical connectionpads of the electronic chip and of the carrier substrate; placing anadditional electrical connection wire between the additional pads andforming electrical junctions between the ends of the additional wire andadditional pads; and producing the local conductive shield such thatthis local conductive shield makes contact with the additionalelectrical connection wire and/or with at least one of the additionalpads.

An electronic device is also proposed which comprises: a carriersubstrate; an electronic chip mounted on the carrier substrate; at leastone electrical connection wire connecting an electrical connection padof the carrier substrate and an electrical connection pad of theelectronic chip; a dielectric layer made of a dielectric material on topof a zone of the electronic chip and of the carrier substrate, includingthe electrical connection wire, the junctions and the pads, such thatthis dielectric material forms a local dielectric coating which at leastpartially surrounds the electrical connection wire and at leastpartially covers the junctions and the pads; and a local conductiveshield made of an electrically conductive material at least partiallycovering the local dielectric coating.

The local dielectric coating may completely surround the electricalconnection wire and completely cover the pads and the junctions and thelocal conductive shield may completely cover the local dielectriccoating.

The device may comprise at least one additional electrical connectionwire connecting an electrical connection pad of the carrier substrateand an electrical connection pad of the electronic chip, the localconductive shield making contact with the additional electricalconnection wire and/or with at least one of these electrical connectionpads.

BRIEF DESCRIPTION OF THE DRAWINGS

An electronic device and a mode of fabrication will now be described byway of non-limiting examples, which are illustrated by the appendeddrawings in which:

FIG. 1 represents a cross-sectional view of an electronic device duringmanufacture, in one manufacturing step;

FIG. 2 represents a view from above of the electronic device of FIG. 1 ;

FIG. 3 represents a cross-sectional view of the electronic device duringmanufacture, in a later manufacturing step;

FIG. 4 represents a view from above of the electronic device of FIG. 3 ;

FIG. 5 represents a cross-sectional view of the electronic device duringmanufacture, in a later manufacturing step, showing the electronicdevice obtained;

FIG. 6 represents a view from above of the electronic device of FIG. 5 ;

FIG. 7 represents a cross-sectional view of an electronic device duringmanufacture, in one manufacturing step;

FIG. 8 represents a view from above of the electronic device of FIG. 7 ;

FIG. 9 represents a cross-sectional view of the electronic device duringmanufacture, in a later manufacturing step;

FIG. 10 represents a view from above of the electronic device of FIG. 9;

FIG. 11 represents a cross-sectional view of the electronic deviceduring manufacture, in a later manufacturing step, showing theelectronic device obtained;

FIG. 12 represents a view from above of the electronic device of FIG. 11;

FIG. 13 represents a cross-sectional view of an electronic device duringfabrication, in one step of fabrication;

FIG. 14 represents a view from above of the electronic device of FIG. 13;

FIG. 15 represents a cross-sectional view of the electronic deviceduring fabrication, in a later step of fabrication;

FIG. 16 represents a view from above of the electronic device of FIG. 15;

FIG. 17 represents a view from above of the electronic device duringfabrication, in a later step of fabrication;

FIG. 18 represents a cross-sectional view of the electronic deviceduring fabrication, in a later step of fabrication, showing theelectronic device obtained; and

FIG. 19 represents a view from above of the electronic device of FIG. 18.

DETAILED DESCRIPTION

As illustrated in FIGS. 1 and 2 , an electronic device 1 comprises acarrier substrate 2 and an electronic chip 3, including integratedcircuits, a back face 4 of which is fixed to a front face 5 of thecarrier substrate 2 by means of a layer of adhesive (not shown).

The carrier substrate 2 is made of a dielectric material and includes anintegrated electrical connection network 6, for connecting to one ormore metal levels, which comprises front exposed electrical connectionpads 7 and 8 of the front face 5 which are located laterally at adistance from a flank 9 of the electronic chip 3 and in proximity of oneanother.

The electronic chip 3 comprises front exposed electrical connection pads10 and 11 of a front face 12 of this electronic chip 3, opposite itsback face 4, which are located at a distance from the flank 9 of theelectronic chip 3, not far from the front pads 7 and 8 of the carriersubstrate 2.

Steps for the purpose of forming electrical connections between the pads7 and 10 and, optionally, the pads 8 and 11, of the carrier substrate 2and the electronic chip 3, respectively, will now be described.

In a step illustrated in FIGS. 1 and 2 , on the one hand a bareelectrical connection wire (also referred to as a bonding wire) 13 isput into place between the exposed electrical connection pads 7 and 10,and electrical junctions 14 and 15 are formed, by means of soldering,between the ends of the electrical connection wire 13 and the pads 7 and10, respectively, and, on the other hand, an additional electricalconnection wire 16 is put into place between the additional exposedelectrical connection pads 8 and 11, and electrical junctions areformed, by means of soldering, between the end portions of theelectrical connection wire 16 and the pads 8 and 11, respectively. Theelectrical connection wires 13 and 16 are neighboring but at a distancefrom one another.

This operation of putting the electrical connection wires 13 and 16 intoplace may be carried out using a specialized wire-bonding machine.

In a later step illustrated in FIGS. 3 and 4 , a determined amount of anadhesive liquid dielectric material is locally distributed on top of theelectrical wire 13, such that this dielectric material completelysurrounds the electrical connection wire 13 and completely covers thepads 7 and 10 and the junctions 14 and 15. After hardening, thisdielectric material forms a local dielectric coating 17.

This operation may be carried out, for example, using a specialized toolcomprising a dispensing syringe 18 capable of delivering at least onecalibrated drop of the liquid dielectric material on top of theelectrical connection wire 13, this liquid dielectric material flowingultimately to surround the electrical connection wire 12 and to coverthe pads 7 and 10 and the junctions 14 and 15, in particular by means ofwetting or capillary effect.

Next, the liquid dielectric material is hardened in order to form thedielectric coating 17, either by virtue of its intrinsic hardeningqualities at room temperature or by hardening under the effect of a heatsource or a source of light radiation. For example, the dielectricmaterial may be a suitable epoxy resin.

In a later step illustrated in FIGS. 5 and 6 , a determined amount of anelectrically conductive adhesive liquid material is locally distributedon top of the dielectric coating 17 and potentially on top of theelectrical connection wire 16 such that this conductive materialcompletely surrounds the dielectric coating 17 and makes contact withthe electrical connection wire 16 and/or the pads 8 and 11, thisconductive material potentially overflowing onto the front faces 5 and12 of the carrier substrate 2 and of the electronic chip 3. Afterhardening, this conductive material forms a local electricallyconductive shield 19 which is as close as possible to the electricalconnection wire 13 and is connected to the electrical connection wire 16and to the pads 8 and 11.

This operation may be carried out, for example, using a specializedcontrolled tool comprising a dispensing syringe 20, capable ofdelivering at least one calibrated drop of the liquid conductivematerial, this liquid conductive material flowing in particular by meansof wetting or capillary effect.

Next, the liquid conductive material is hardened in order to form thelocal conductive shield 19, by virtue of its intrinsic hardeningqualities at room temperature or by hardening under the effect of a heatsource or a source of light radiation. For example, the conductivematerial may be an epoxy resin filled with metal particles.

The finished electronic device 1 is thus obtained.

The electrical connection wire 13 is intended to convey electricalsignals between the pads 7 and 10 of the carrier substrate 2 and theelectronic chip 3. The conductive shield 19 provides electromagneticprotection for these electrical signals.

The pads 8 and 11, which are connected by the electrical connection wire16, form ground pads of the electrical circuits of the electronic device1. Thus, the conductive shield 19, which is connected to the pads 8 and11 and to the electrical connection wire 16, is connected to the groundof the electrical circuits of the electronic device 1.

According to one variant embodiment, it would be possible for the localdielectric coating 17 to cover only one of the pads 7 and 10 and anadjacent portion of the electrical connection wire 13 and it would bepossible for the local conductive shield 19 to partially cover thisreduced local dielectric coating 17 without this reduced localconductive shield 19 coming into contact with the electrical connectionwire 13.

According to one variant embodiment, it would be possible to do omit theelectrical connection wire 16.

Of course, the electronic device 1 may comprise other electricalconnection wires 13 connecting other pads 7 and 10 of the carriersubstrate 2 and of the electronic chip 3, and other electricalconnection wires 16 connecting other pads 8 and 11 of the carriersubstrate 2 and of the electronic chip 3, which are also equipped withlocal dielectric coatings 17 and local conductive shields 19, therespective steps of the production of which would be the same.

According to one variant embodiment, it would be possible for one localconductive shield 19 to be shared by multiple neighboring electricalconnection wires 13 and to locally cover the front face 5 of the carriersubstrate and/or the front face 12 of the electronic chip 3, such thatthis extended local conductive shield 19 would form electromagneticprotection for some of the electronic circuits of the electronic device1. Such an extended local conductive shield 19 could, for example, beformed by means of physical vapor deposition (PCV) of a metal material,for example copper or aluminum. In this case, it would be possible toprovide a single ground electrical connection wire 16. Still in thiscase, and as a variant, the extended local conductive shield 19 could beconnected to ground by providing at least one electrical connection pad8 of the carrier substrate 2 that is not covered by the dielectriccoating 17.

According to one variant embodiment, the carrier substrate 2 couldcomprise a metal frame comprising a platform upon which the electronicchip 3 would be mounted, the electrical connection wires 13 and 16connecting the electronic chip 3 to peripheral leads of this frame.

As illustrated in FIGS. 7 and 8 , an electronic device 1 comprises acarrier substrate 2 and an electronic chip 3, including integratedcircuits, a back face 4 of which is fixed to a front face 5 of thecarrier substrate 2 by means of a layer of adhesive (not shown).

The carrier substrate 2 is made of a dielectric material and includes anintegrated electrical connection network 6, for connecting to one ormore metal levels, which comprises front exposed electrical connectionpads 7 and 8 of the front face 5 which are located laterally at adistance from a flank 9 of the electronic chip 3 and in proximity of oneanother.

The electronic chip 3 comprises front exposed electrical connection pads10 and 11 of a front face 12 of this electronic chip 3, opposite itsback face 4, which are located at a distance from the flank 9 of theelectronic chip 3, not far from the front pads 7 and 8 of the carriersubstrate 2.

Steps for the purpose of forming electrical connections between the pads7 and 10 and, optionally, the pads 8 and 11, of the carrier substrate 2and the electronic chip 3, respectively, will now be described.

In a step illustrated in FIGS. 7 and 8 , an electrical connection wire113, surrounded by a sheath 113 a made of a dielectric material, is putinto place between the exposed electrical connection pads 7 and 10, andelectrical junctions 114 and 115 are formed, by means of soldering,between the ends of the electrical connection wire 113 and the pads 7and 10, respectively. Furthermore, an additional electrical connectionwire 116, either bare or surrounded by an insulating sheath, is put intoplace between the additional exposed electrical connection pads 8 and11, and electrical junctions are formed, by means of soldering, betweenthe end portions of the electrical connection wire 116 and the pads 8and 11, respectively. The electrical connection wires 113 and 116 areneighboring but at a distance from one another.

This operation of putting the electrical connection wires 113 and 116into place may be carried out using a specialized wire-bonding machine.

In a later step illustrated in FIGS. 9 and 10 , a determined amount ofan adhesive liquid dielectric material is locally distributed on top ofthe pad 7 and/or the junction 114 and/or the end portion of theinsulating sheath 113 a that is adjacent to the junction 114, such thatthis dielectric material completely covers the pad 7 and the junction114 and completely surrounds the end portion of the insulating sheath113 a that is adjacent to the junction 114. After hardening, thisdielectric material forms a first local dielectric coating 117 a.

In an equivalent manner, a determined amount of an adhesive liquiddielectric material is locally distributed on top of the pad 10 and/orthe junction 115 and/or the end portion of the insulating sheath 113 athat is adjacent to the junction 115, such that this dielectric materialcompletely covers the pad 7 and the junction 115 and completelysurrounds the end portion of the insulating sheath 113 a that isadjacent to the junction 115. After hardening, this dielectric materialforms a second local dielectric coating 117 b.

These operations may be carried out, for example, using a specializedcontrolled tool comprising a dispensing syringe 118 capable ofdelivering at least one calibrated drop of the liquid dielectricmaterial, this liquid dielectric material flowing ultimately to coverthe pads 7 and 10 and the junctions 114 and 115 and to surround thecorresponding end portions of the insulating sheath 113 a, in particularby means of wetting or capillary effect.

Next, the liquid dielectric material is hardened in order to form thedielectric coatings 117 a and 117 b, by virtue of its intrinsichardening qualities at room temperature or by hardening under the effectof a heat source or a source of light radiation. For example, thedielectric material may be a suitable epoxy resin.

In a later step illustrated in FIGS. 11 and 12 , a determined amount ofan electrically conductive adhesive liquid material is locallydistributed such that this conductive material completely surrounds theinsulating sheath 113 a, covers the local dielectric coatings 117 a and117 b and makes contact with the electrical connection wire 116 and/orthe pads 8 and 11, this conductive material potentially overflowing ontothe front faces 5 and 12 of the carrier substrate 2 and of theelectronic chip 3. After hardening, this conductive material forms alocal electrically conductive shield 119 which is as close as possibleto the electrical connection wire 113 and is connected to the electricalconnection wire 116 and to the pads 8 and 11.

This operation may be carried out, for example, using a specialized toolcomprising a dispensing syringe 120, capable of delivering at least onerespective calibrated drop of the liquid conductive material, thisliquid conductive material flowing in particular by means of wetting orcapillary effect.

Next, the liquid conductive material is hardened in order to form thelocal conductive shield 119, by virtue of its intrinsic hardeningqualities at room temperature or by hardening under the effect of a heatsource or a source of light radiation. For example, the conductivematerial may be an epoxy resin filled with metal particles.

The electrical connection wire 113 is intended to convey electricalsignals between the pads 7 and 10 of the carrier substrate 2 and theelectronic chip 3. The conductive shield 119 provides electromagneticprotection for these electrical signals.

The pads 8 and 11, which are connected by the electrical connection wire116, form ground pads of the electrical circuits of the electronicdevice 1. Thus, the conductive shield 119, which is connected to thepads 8 and 11 and to the electrical connection wire 116, is connected tothe ground of the electrical circuits of the electronic device 1.

According to one variant embodiment, it would be possible to provideonly one of the local dielectric coatings 117 a and 117 b and it wouldbe possible for the local conductive shield 119 to partially cover thislocal dielectric coating and a portion of the sheath 113 a without thisreduced local conductive shield 119 coming into contact with theelectrical connection wire 113 and the opposite pad.

According to one variant embodiment, it would be possible to do omit theelectrical connection wire 116.

Of course, the electronic device 1 may comprise other electricalconnection wires 113 connecting other pads 7 and 10 of the carriersubstrate 2 and of the electronic chip 3, and other electricalconnection wires 116 connecting other pads 8 and 11 of the carriersubstrate 2 and of the electronic chip 3, which are also equipped withlocal dielectric coatings 117 a and 117 b and local conductive shields119, the respective steps of the production of which would be the same.

According to one variant embodiment, it would be possible for one localconductive shield 119 to be shared by multiple neighboring electricalconnection wires 113 and to locally cover the front face 5 of thecarrier substrate and/or the front face 12 of the electronic chip 3,such that this extended local conductive shield 119 would formelectromagnetic protection for some of the electronic circuits of theelectronic device 1. Such an extended local conductive shield 119 could,for example, be formed by means of physical vapor deposition (PCV) of ametal material, for example copper or aluminum. In this case, it wouldpotentially be possible to provide a single ground electrical connectionwire 116. Still in this case and as a variant, the extended localconductive shield 119 could be connected to ground by providing at leastone electrical connection pad 8 of the carrier substrate 2 that is notcovered by the dielectric coating 117.

According to one variant embodiment, the carrier substrate 2 couldcomprise a metal frame comprising a platform upon which the electronicchip 3 would be mounted, the electrical connection wires 113 and 116connecting the electronic chip 3 to peripheral leads of this frame.

As illustrated in FIGS. 13 and 14 , an electronic device 1 comprises acarrier substrate 2 and an electronic chip 3, including integratedcircuits, a back face 4 of which is fixed to a front face 5 of thecarrier substrate 2 by means of a layer of adhesive (not shown).

The carrier substrate 2 is made of a dielectric material and includes anintegrated electrical connection network 6, for connecting to one ormore metal levels, which comprises front exposed electrical connectionpads 7 and 8 of the front face 5 which are located laterally at adistance from a flank 9 of the electronic chip 3 and in proximity of oneanother.

The electronic chip 3 comprises front exposed electrical connection pads10 and 11 of a front face 12 of this electronic chip 3, opposite itsback face 4, which are located at a distance from the flank 9 of theelectronic chip 3, not far from the front pads 7 and 8 of the carriersubstrate 2.

Steps for the purpose of forming electrical connections between the pads7 and 10 and, optionally, the pads 8 and 11, of the carrier substrate 2and of the electronic chip 3, respectively, will now be described.

In a step illustrated in FIGS. 13 and 14 , an electrical connection wire(also referred to as a bonding wire) 213 is put into place between theexposed electrical connection pads 7 and 10 and electrical junctions 214and 215 are formed, by means of soldering, between the ends of theelectrical connection wire 213 and the pads 7 and 10, respectively.

This operation of putting the electrical connection wire 213 into placemay be carried out using a specialized wire-bonding machine.

In a later step illustrated in FIGS. 15 and 16 , a determined amount ofan adhesive liquid dielectric material is distributed on top of a zoneof the front faces 5 and 12 of the carrier substrate 2, of theelectronic chip 3 and of the electrical connection wire 213, such thatthis dielectric material at least partially covers the faces 5 and 12,the pads 7, 8, 10 and 12 and the junctions 214 and 215 and completelysurrounds the electrical connection wire 213.

After hardening, this dielectric material forms a dielectric layer 217 aon top of the front faces 5 and 12 of the carrier substrate 2 and of theelectronic chip 3 and forms a local dielectric coating 217 b that coversthe pads 7, 8, 10 and 12 and the junctions 214 and 215 and surrounds theelectrical connection wire 213, the dielectric layer 217 a and the localdielectric coating 217 b extending one another.

This operation may be carried out, for example, using a specialized toolcomprising a controlled dispensing syringe 218, capable of delivering atleast one respective calibrated drop of the liquid conductive material,this liquid conductive material flowing in particular by means ofwetting or capillary effect. As a variant, this operation may be carriedout by immersing the entire electronic device 1 in a bath of dielectricmaterial. The dielectric material may alternatively be distributed bymeans of sputtering (for example, spraying).

Next, the liquid dielectric material is hardened in order to form thedielectric coatings 217 a and 217 b, by virtue of its intrinsichardening qualities at room temperature or by hardening under the effectof a heat source or a source of light radiation. For example, thedielectric material may be a suitable epoxy resin or else apoly-para-xylylene polymer, commonly referred to as parylene. In anembodiment, the dielectric coatings 217 a and 217 b have a substantiallyuniform coating thickness over the surfaces of the electrical connectionwire 213, the pads 7 and 10, the chip 3 and the substrate 2.

In a later step illustrated in FIG. 17 , openings 216 a and 216 b aremade through the dielectric layer 217 a, for example by means ofetching, above the pads 8 and 11. Next, an additional electricalconnection wire (also referred to as a bonding wire) 216 is put intoplace between the additional exposed electrical connection pads 8 and 11and electrical junctions are formed, by means of soldering, between theends of the electrical connection wire 216 and the pads 8 and 11,respectively.

This operation of putting the electrical connection wire 216 into placemay be carried out using a specialized wire-bonding machine.

In a later step illustrated in FIGS. 18 and 19 , a determined amount ofan electrically conductive adhesive liquid material is locallydistributed such that this conductive material completely surrounds theinsulating coating 217 b, covers the local dielectric coating 217 a andmakes contact with the electrical connection wire 216 and/or the pads 8and 11, this conductive material potentially overflowing onto the frontfaces 5 and 12 of the carrier substrate 2 and of the electronic chip 3.After hardening, this conductive material forms a local electricallyconductive shield 219 which is as close as possible to the electricalconnection wire 213 and is connected to the electrical connection wire216 and to the pads 8 and 11.

This operation may be carried out, for example, using a specializedcontrolled tool comprising a controlled dispensing syringe 220, capableof delivering at least one calibrated drop of the liquid conductivematerial, this liquid conductive material flowing in particular by meansof wetting or capillary effect.

Next, the liquid conductive material is hardened in order to form thelocal conductive shield 219, by virtue of its intrinsic hardeningqualities at room temperature or by hardening under the effect of a heatsource or a source of light radiation. For example, the conductivematerial may be an epoxy resin filled with metal particles.

The finished electronic device 1 is then obtained.

The electrical connection wire 213 is intended to convey electricalsignals between the pads 7 and 10 of the carrier substrate 2 and of theelectronic chip 3. The conductive shield 219 forms electromagneticprotection for these electrical signals.

The pads 8 and 11, which are connected by the electrical connection wire216, form ground pads of the electrical circuits of the electronicdevice 1. Thus, the conductive shield 219, which is connected to thepads 8 and 11 and to the electrical connection wire 216, is connected tothe ground of the electrical circuits of the electronic device 1.

According to one variant embodiment, the local conductive shield 219could partially cover the local dielectric coating 217 b.

According to one variant embodiment, it would be possible to do awaywith the electrical connection wire 216.

Of course, the electronic device 1 may comprise other electricalconnection wires 213 connected to other pads 7 and 10 of the carriersubstrate 2 and of the electronic chip 3, and other electricalconnection wires 216 connecting other pads 8 and 11 of the carriersubstrate 2 and of the electronic chip 3, which are also equipped withlocal dielectric coatings 217 b and local conductive shields 219, therespective steps of the production of which would be the same.

According to one variant embodiment, it would be possible for one localconductive shield 219 to be shared by multiple neighboring electricalconnection wires 213 and to locally cover the front face 5 of thecarrier substrate and/or the front face 12 of the electronic chip 3,such that this extended local conductive shield 219 would formelectromagnetic protection for some of the electronic circuits of theelectronic device 1. In this case, it would be possible to provide asingle ground electrical connection wire 216.

According to one variant embodiment, the carrier substrate 2 couldcomprise a metal frame comprising a platform upon which the electronicchip 3 would be mounted, the electrical connection wires 213 and 216connecting the electronic chip 3 to peripheral leads of this frame.

1. A method, comprising: placing an electrical connection wire betweenan exposed electrical connection pad of an electronic chip and anexposed electrical connection pad of a carrier substrate on which theelectronic chip is mounted and forming electrical junctions between endsof the electrical connection wire and the exposed electrical connectionpads; producing a dielectric layer made of a dielectric material on topof a zone of the electronic chip and of the carrier substrate, includingthe electrical connection wire, the electrical junctions and the exposedelectrical connection pads, such that the dielectric layer forms a localdielectric coating which at least partially surrounds the electricalconnection wire and at least partially covers the electrical junctionsand the exposed electrical connection pads; and producing a localconductive shield made of an electrically conductive material which atleast partially covers the local dielectric coating.
 2. The methodaccording to claim 1, wherein producing the dielectric layer comprisesdistributing a determined amount of the dielectric material in a liquidstate and hardening said dielectric material.
 3. The method according toclaim 2, wherein the dielectric material is distributed by means ofsputtering.
 4. The method according to claim 1, wherein producing thelocal conductive shield comprises distributing a determined amount of anelectrically conductive material in a liquid state and hardening saidelectrically conductive material.
 5. The method according to claim 4,where the electrically conductive material is distributed using acontrolled tool.
 6. The method according to claim 5, wherein thecontrolled tool is a dispensing syringe.
 7. The method according toclaim 1, wherein producing the dielectric layer comprises completelysurrounding the electrical connection wire and completely covering theexposed electrical connection pads and the electrical junctions andwherein producing the local conductive shield comprises completelycovering said local dielectric coating.
 8. The method according to claim1, further comprising the following steps: producing openings in thedielectric layer above additional electrical connection pads of theelectronic chip and of the carrier substrate; placing an additionalelectrical connection wire between the additional electrical connectionpads and forming additional electrical junctions between the ends of theadditional electrical connection wire and the additional electricalconnection pads; and wherein producing the local conductive shieldcomprises producing the local conductive shield to make contact with atleast one of the additional electrical connection wire and at least oneof the additional electrical connection pads.
 9. The method according toclaim 1, wherein producing a dielectric layer comprises depositing thedielectric layer with a substantially uniform thickness.
 10. A method,comprising the following steps: mounting an electronic chip to a carriersubstrate; connecting a bonding wire between an electrical connectionpad of the electronic chip and an electrical connection pad of thecarrier substrate; flowing a liquid dielectric material to coat saidbonding wire and at least a portion of each of the electronic chip andthe carrier substrate; hardening the liquid dielectric material to forma dielectric layer of substantially uniform thickness surrounding thebonding wire and on surfaces of said portion of each of the electronicchip and the carrier substrate; flowing a liquid electrically conductivematerial to coat the dielectric layer; and hardening the liquidelectrically conductive material to form a conductive shield surroundingthe dielectric layer on the bonding wire.
 11. The method of claim 10,further comprising: forming openings in the dielectric layer to exposean additional electrical connection pad of the electronic chip and anadditional electrical connection pad of the carrier substrate;connecting an additional bonding wire between the additional electricalconnection pad of the electronic chip and the additional electricalconnection pad of the carrier substrate; wherein flowing the liquidelectrically conductive material further comprises flowing the liquidelectrically conductive material to coat the additional bonding wire;and wherein hardening the liquid electrically conductive materialfurther comprises hardening the liquid electrically conductive materialto form the conductive shield surrounding the additional bonding wire.12. A method for making an electrical connection between an electronicchip and a carrier plate on which the electronic chip is mounted,comprising: installing at least one electrical connection wire betweenan exposed electrical connection pad of the electronic chip and anexposed electrical connection pad of the carrier plate and makingelectrical junctions between ends of the at least one electricalconnection wire and the exposed electrical connection pads; producing adielectric layer made of a dielectric material over an area of theelectronic chip and the carrier plate, including the at least oneelectrical connection wire, the electrical junctions and the exposedelectrical connection pads, by dispensing a determined amount of thedielectric material in a liquid state and hardening said dielectricmaterial, wherein the dielectric layer produces a local dielectriccoating surrounding the at least one electrical connection wire andcovers the electrical junctions and the exposed electrical connectionpads, and producing a local conductive shield made of an electricallyconductive material which at least partially covers the local dielectriccoating, wherein producing the local conductive shield comprises:locally dispensing a determined amount of an electrically conductivematerial in a liquid state, in the form of a calibrated drop which flowsby capillary or wetting effect, through use of a controlled toolcomprising a controlled dispensing syringe; and hardening saidconductive material to produce the local conductive shield around the atleast one electrical connection wire and the electrical junctions. 13.The method according to claim 12, wherein producing the dielectric layercomprises spraying the dielectric material.
 14. The method according toclaim 12, further comprising: producing openings in the dielectric layerabove complementary electrical connection pads of the electronic chipand of the carrier plate; installing a complementary electricalconnection wire between the complementary electrical connection pads;and producing electrical junctions between ends of the complementaryelectrical connection wire and the complementary electrical connectionpads, and wherein producing the local conductive shield comprisesforming the local conductive shield in contact with one or more of thecomplementary electrical connection wire and at least one of thecomplementary electrical connection pads.
 15. A method, comprising thefollowing steps: placing an electrical connection wire between anexposed electrical connection pad of an electronic chip and an exposedelectrical connection pad of a carrier substrate to which the electronicchip is mounted and forming electrical junctions between the ends of theelectrical connection wire and the pads, the electrical connection wirebeing equipped with an insulating sheath made of a dielectric materialwhich surrounds the electrical connection wire except at exposed ends ofthe electrical connection wire; producing a local dielectric coatingmade of a dielectric material, which at least partially covers at leastone of the electrical connection pads, the electrical junction andexposed end of the electrical connection wire adjacent thereto and atleast partially surrounds an end portion of the insulating sheathadjacent to the electrical junction; and producing a conductive shieldmade of an electrically conductive material which at least partiallycovers said dielectric coating and at least partially surrounds theinsulating sheath.
 16. The method according to claim 15, whereinproducing the local dielectric coating comprises distributing adetermined amount of the dielectric material in the liquid state andhardening said dielectric material.
 17. The method according to claim16, wherein distributing comprises using a controlled tool to dispensethe dielectric material in the liquid state.
 18. The method according toclaim 17, wherein the controlled tool is a dispensing syringe.
 19. Themethod according to claim 15, wherein producing the conductive shieldcomprises distributing a determined amount of an electrically conductivematerial in the liquid state and hardening said electrically conductivematerial.
 20. The method according to claim 19, wherein producing theconductive shield comprises using a controlled tool to dispense theelectrically conductive material in the liquid state.
 21. The methodaccording to claim 20, wherein the controlled tool is a dispensingsyringe.
 22. The method according to claim 15, wherein producing thelocal dielectric coating comprises: producing a first local dielectriccoating on a first electrical connection pad, a first electricaljunction and the exposed end of the electrical connection wire adjacentthereto and which at least partially surrounds a first end portion ofthe insulating sheath adjacent to the first electrical junction; andproducing a second local dielectric coating on a second electricalconnection pad, a second electrical junction and the exposed end of theelectrical connection wire adjacent thereto and which at least partiallysurrounds a second end portion of the insulating sheath adjacent to thesecond electrical junction.
 23. The method according to claim 22,wherein producing the conductive shield comprises providing theelectrically conductive material to cover the first and second localdielectric coatings and surround the insulating sheath between the firstand second local dielectric coatings.
 24. The method according to claim15, further comprising the following steps: placing an additionalelectrical connection wire between an exposed additional electricalconnection pad of the electronic chip and an exposed additionalelectrical connection pad of the carrier substrate and formingadditional electrical junctions between ends of the additionalelectrical connection wire and the exposed additional electricalconnection pads; and wherein producing the conductive shield comprisesproducing the conductive shield to make contact with at least one of theadditional electrical connection wire and at least one of the exposedadditional electrical connection pads.
 25. The method according to claim15, wherein the electronic chip further includes an exposed additionalelectrical connection pad, and wherein producing the conductive shieldcomprises producing the conductive shield to make contact with saidexposed additional electrical connection pad.
 26. The method accordingto claim 15, wherein the carrier substrate further includes an exposedadditional electrical connection pad, and wherein producing theconductive shield comprises producing the conductive shield to makecontact with said exposed additional electrical connection pad.
 27. Amethod, comprising the following steps: placing an electrical connectionwire between an exposed electrical connection pad of an electronic chipand an exposed electrical connection pad of a carrier substrate to whichthe electronic chip is mounted and forming electrical junctions betweenthe ends of the electrical connection wire and the pads; producing adielectric coating made of a dielectric material, which completelycovers the electrical connection wire and completely covers theelectrical junctions and further at least partially covers each of theelectrical connection pads; and producing a conductive shield made of anelectrically conductive material which at least partially covers saiddielectric coating at said electrical connection pads and completelycovers said dielectric coating at said electrical junctions and furthercompletely surrounds said dielectric coating at said electricalconnection wire.
 28. The method according to claim 27, wherein producingthe dielectric coating comprises distributing a determined amount of thedielectric material in the liquid state and hardening said dielectricmaterial.
 29. The method according to claim 28 wherein distributingcomprises using a controlled tool to dispense the dielectric material inthe liquid state.
 30. The method according to claim 29, wherein thecontrolled tool is a dispensing syringe.
 31. The method according toclaim 27, wherein producing the conductive shield comprises distributinga determined amount of an electrically conductive material in the liquidstate and hardening said electrically conductive material.
 32. Themethod according to claim 31, wherein producing the conductive shieldcomprises using a controlled tool to dispense the electricallyconductive material in the liquid state.
 33. The method according toclaim 32, wherein the controlled tool is a dispensing syringe.
 34. Themethod according to claim 27, further comprising the following steps:placing an additional electrical connection wire between an exposedadditional electrical connection pad of the electronic chip and anexposed additional electrical connection pad of the carrier substrateand forming additional electrical junctions between ends of theadditional electrical connection wire and the exposed additionalelectrical connection pads; and wherein producing the conductive shieldcomprises producing the conductive shield to make contact with theadditional electrical connection wire and at least one of the exposedadditional electrical connection pads.
 35. The method according to claim27, wherein the carrier substrate further includes an exposed additionalelectrical connection pad and wherein producing the conductive shieldfurther comprises producing the conductive shield to make contact withthe exposed additional electrical connection pad.
 36. The methodaccording to claim 27, wherein the electronic chip further includes anexposed additional electrical connection pad and wherein producing theconductive shield further comprises producing the conductive shield tomake contact with the exposed additional electrical connection pad.